Thyroid physiologic adaptations in pregnancy may be confused with pathologic changes. Human chorionic gonadotropin rises early in pregnancy, stimulating thyrotropin secretion and suppressing thyroid stimulating hormone. These chemical changes are often seen in hyperemesis gravidarum and gestational transient thyrotoxicosis. Therefore, mild thyrotoxicosis may be difficult to differentiate from early pregnancy thyroxine stimulation. However, overt hyperthyroidism usually includes classic symptoms seen outside of pregnancy in addition to suppressed TSH and T4 levels. Treatment includes thionamides propylthiouracil and methimazole. Thyroid ablation is contraindicated in pregnancy. Often, in affected women, the fetus is euthyroid, but neonates can develop hyper or hypothyroidism with or without a goiter. Lastly, thyroid storm, though rare, is life threatening. Often presenting as a hypermetabolic state with cardiomyopathy and pulmonary hypertension, it generally results from decompensation from preeclampsia, anemia, sepsis, or surgery. Treatment requires intensive care level management, with initiation of thionamides, iodine, and beta blockers.
This review contains 2 figures, 4 tables and 38 references.
Keywords: Thyroid-releasing hormong, thyroid-stimulating hormone, thyromegaly, thyroid-stimulating immunoglobulins, thryotoxicosis, thionamides, thyroid storm
Thyroid Storm Caused by Hyperemesis Gravidarum
